You would think that you could sleep through all but the worst pain – with the help of pain and sleep medication if the pain is severe enough of course.
However, even dull persistent pain can keep you from sleeping. It can prevent you falling asleep in the first place or wake you in the night and prevent you from falling asleep again.
Chronic pain is known to result in chronic sleeplessness, apparently resistant to all but the strongest sleeping pills, and even those when you become habituated to them.
This begs the question – why would pain wake you up if you are unconscious and so cannot feel it?
The answer is that you do feel it when you are unconscious! You just don’t know you are feeling it.
Why does pain cause sleeplessness (and continually disrupt your attempts to sleep) because:
- Pain is an indicator that the body is under threat. Your ‘sleeping brain’ will wake you to deal with that threat. It will do so at the point where any painkillers you have taken start to wear off.
- You might be unaware, but your brain has not switched off. It ‘feels’ the pain, even if you do not.
- As a result, the awareness of pain can be processed in REM sleep as something disturbing in a dream, and this can wake you.
- Your brain and adrenal system may respond to the pain – the threat and the physical experience – with acute anxiety (fight or flight response) that wakes you.
- Chronic lack of sleep, or poor-quality sleep with frequent waking and anxiety, can exacerbate chronic pain. Though this connection is poorly understood, it is no longer doubted. Increased pain exaggerates the above effects. This is especially true as it is more resistant to pain killers and sleep medication.
Pain creates one response in the body, while sleep demands another. The pain response resulting from release of adrenalin, is antagonistic to the sleep response, which is homeostasis. You experience this ‘contest’ as sleeplessness – along with the often ‘false’ perception that it’s the conscious experience of the pain itself keeping you awake.